Plant cytochrome P450s are now known to be involved in the metabolism and detoxification of numerous pesticides. Much of the evidence has been gathered via traditional chemistry techniques (Shuler, 15 Crit Rev Plant Sci 235 (1996); Bolwell et al., 37 Phytochemistry 1491(1994) and Frear et al., 8 Phytochemistry 2157 (1969)), or through use of mammalian or bacterial genes in plants (Shiota et al., 106 Plant Physiol 17 (1994) and O""Keefe et al., 105 Plant Physiol 473 (1994)).
Recently, however, endogenous plant P450s have been cloned and expressed using molecular biology techniques. For example, CYP73A1, a cytochrome isolated from Jerusalem artichoke was recently shown to metabolize chlortoluron (Pierrel, 224 Eur J Biochem 835 (1994). Likewise, several soybean P450s were cloned and one was shown to metabolize linuron and chlortoluron (Presentation, Weed Sci Soc of Amer (February 1997)).
The most up-to-date source of information on plant P450s is on the internet. As of Jul. 12, 1998, most of the information related to the CYP72A subfamily of P450s on that web site pertained to the Catharanthus (rosens) P450s, although Nicotiana and Arabidopsis P450s were also characterized. The site implied the existence of two CYP72 P450s from Zea mays, although the sequence information was not disclosed for either. The two were assigned separate identifiers by the web site developer. Specifically, the web site stated:
CYP72A Zea mays 
no accession number (318 amino acids)
Mike Persons and Mary Schuler
PCR 4 formerly CYp95A1 (missnamed due to a frame shift in the PCR fragment)
CPY72A1 Zea mays (maize)
no accession number
Mike Barrett
clone A8 most like PCR fragment PCR4 from Mike Persans and Mary Schuler. The PCR4 fragment was missnamed as CYP95A1 due to a frame shift error in the sequence in the I helix region, also like Arabidopsis GSS BAC end fragment B24203 (67? identical) submitted to nomenclature committee.
The above can be found at http://drnelson.utmem.edu/biblioD.html#72A.
The concept of a multiple pesticide metabolizing P450 in corn was first proposed during the Ph.D. Dissertation of Laura Boldt on Apr. 15, 1992. FIG. 12 in the present disclosure is the table from her thesis, which indicates that corn line GA209 is not only sensitive to bentazon, but also to the herbicides imazethapyr, nicosulfuron and primisulfuron. In further research by Roger Baerg, it was shown that the in-vitro metabolism of the herbicides nicosulfuron, chlorimuron, bentazon, imazethapyr, and the insecticide malathion are all inhibited by the insecticide terbufos-sulfone (FIG. 13xe2x80x94from Baerg et al., 55 Pesticide Biochemistry and Physiology 10 (1996), initially disclosed Nov. 4, 1994 in dissertation form).
Citation of the above documents is not intended as an admission that any of the foregoing is pertinent prior art. All statements as to the date or representation as to the contents of these documents is based on subjective characterization of information available to the applicant, and does not constitute any admission as to the accuracy of the dates or contents of these documents.
It is therefore an object of the present invention to provide compounds useful to protect plants from the otherwise detrimental effects of a broad spectrum of pesticides, including negative effects of herbicides and/or insecticides.
It is a further object to provide assays for discovery of new pesticide safeners, including herbicide and/or insecticide safeners.
It is yet another object to provide assays for discovery of new pesticides, including herbicide and/or insecticide assays.
It is yet another object to provide tools for pesticide metabolite analysis, including herbicide and/or insecticide metabolite analysis.
Moreover, for the purposes of the present invention, the term xe2x80x9caxe2x80x9d or xe2x80x9canxe2x80x9d entity refers to one or more of that entity; for example, xe2x80x9ca proteinxe2x80x9d or xe2x80x9ca nucleic acid moleculexe2x80x9d refers to one or more of those compounds or at least one compound. As such, the terms xe2x80x9caxe2x80x9d (or xe2x80x9canxe2x80x9d), xe2x80x9cone or morexe2x80x9d and xe2x80x9cat least onexe2x80x9d can be used interchangeably herein. It is also to be noted that the terms xe2x80x9ccomprisingxe2x80x9d, xe2x80x9cincludingxe2x80x9d, and xe2x80x9chavingxe2x80x9d can be used interchangeably. Furthermore, a compound xe2x80x9cselected from the group consisting ofxe2x80x9d refers to one or more of the compounds in the list that follows, including mixtures (i.e., combinations) of two or more of the compounds. According to the present invention, an isolated, or biologically pure, protein or nucleic acid molecule is a compound that has been removed from its natural milieu. As such, xe2x80x9cisolatedxe2x80x9d and xe2x80x9cbiologically purexe2x80x9d do not necessarily reflect the extent to which the compound has been purified. An isolated compound of the present invention can be obtained from its natural source, can be produced using molecular biology techniques or can be produced by chemical synthesis. In this application, the term xe2x80x9cpesticidexe2x80x9d is used as a generic word for both herbicides and insecticides.